This invention relates to a writing instrument such as a refillable pencil or mechanical pencil. More particularly, the invention relates to a writing instrument of the type in which a cap having a clip is detachably fitted on one end of an elongated cylinder constituting the main body of a writing instrument.
Writing instruments of the aforesaid type having a main body and a cap have long been in wide use. The main body has a cylinder the front end (the writing end) of which is provided with a cap-fitting portion. Contiguous with the cap-fitting portion on the cylinder is a gripping portion located rearwardly of the cap-fitting portion and having an outer peripheral surface provided with a number slip-preventing annular grooves juxtaposed in the axial direction.
When a writing instrument such as a refillable pencil or mechanical pencil is carried about on one's person, the major portion of the main body with the exception of the tip thereof is placed in a pocket or the like, and a fabric or the like on the outer side of the pocket is clamped between the main body of the cap and the clip of the cap fitted onto the tip of the cylinder constituting the main body of the writing instrument. The writing instrument is held in place by the clipping force of the resilient clip.
However, a problem encountered with the conventional writing instrument of the kind described above is that when the cap is subjected to an axially directed external force such as an upwardly acting force that attempts to detach the cap from the cylinder of the main body of the writing instrument while the instrument is being carried one's person, the cap detaches from the fabric on the outer side of the pocket and either or both of the cap and main body may fall out of the pocket.